Date of this Version
Burnam, J.S., S.N. Ellis-Felege, W.E. Palmer, D.C. Sisson, and J.P. Carroll. 2012. Patterns of incubation behavior in northern bobwhites (Colinus virginianus). Pp. 77-88 in C.A Ribic, F.R. Thompson III, and P.J Pietz (eds). Video Surveillance of nesting birds, Studies in Avian Biology (no. 43), University of California Press, Berkeley, CA 240pp.
Patterns of incubation and nesting behavior for many species of birds, especially those with cryptic nests, have been difficult to obtain due to logistical and technological limitations. As a result, little is known about the daily attendance rhythms and behavioral patterns of many species, including the Northern Bobwhite (Colinus virginianus), despite this species being one of the most studied birds in the world. Incubation represents parental investment in offspring, and a multitude of factors may affect investment behaviors, including reproductive ecology, sex and age of parent, habitat quality, clutch age, and timing in the nesting season. Most Northern Bobwhite nests are incubated by a single adult, most often by females, but also by some males. We assessed the nest attendance patterns and parental investment in bob-white clutches (n 118) using continuous near-infrared video of nests being incubated by male or female bobwhites. We found that incubating parents took 0 –3 recesses per day. A single recess was most common for 87% of nest-days, and most of these were during mid-day to late afternoon (12:00 19:00). Mean total daily recess time was 182 min (95% CI: 98–264) for nests that hatched and 224 min (95% CI: 140–308) for nests that failed. We observed no difference between sexes in the number or length of recesses taken, but females initiated recess later in the day (median start time 15:00) than males (median start time 14:00). We found that nest recess length decreased as the clutch got older and increased as the nesting season progressed. Video surveillance systems proved to be a use-ful tool for observing and quantifying patterns of incubation behavior in a ground-nesting species with cryptic nests.